Two-Phase Heat Transfer for Flow in Tubes and Over Rod Bundles With Blockages

Abstract

A study of single- and two-component, two-phase heat transfer mechanisms for vertical flow inside of tubes and over rod bundles with blockages has been made. Existing heat transfer data for air–water flow in tubes with a liquid Reynolds number range of 2000 to 150,000 and void fractions up to 0.40 have been correlated as a function of αGr/Re2. The correlation has also been found to compare well with limited high Prandtl number data obtained with liquids other than water and for flow over rod bundles when an empirical constant is modified. Correlations have also been developed for the heat transfer coefficient in the vicinity of flow blockages in rod bundles. The heat transfer data have been obtained on a four rod bundle with sleeve-type blockages for a Reynolds number range of 230 to 6900 and void fractions up to 0.15. Significant enhancement of the heat transfer coefficient has been observed downstream of the blockages.